Light-sensitive O-quinone diazide containing copying material

ABSTRACT

A light-sensitive copying material comprising at least two organic coating layers on a support, at least one of the coating layers being a light-sensitive layer which comprises an O-quinone diazide compound whose alkali solubility is increased by irradiation with active rays.

This is a continuation of application Ser. No. 643,726, filed Dec. 23,1975, now abandoned, which is a division of application Ser. No.474,465, filed May 29, 1974, now abandoned.

BACKGROUND OF THE INVENTION

1. FIELD OF THE INVENTION

This invention relates to a light-sensitive copying material containingan O-quinone diazide compound as a light-sensitive component.

2. DESCRIPTION OF THE PRIOR ART

It is known that O-quinone diazide compounds decompose at the diazogroup upon radiation with active rays to become carboxyl group-bearingcompounds. When a copying layer containing an O-quinone diazide compoundis imagewise exposed and then treated with an alkaline developer,therefore, the exposed area is removed and the non-exposed area remainsas an image. Accordingly, an O-quinone diazide compound has latelybecome noted as a light-sensitive component of the so-calledpositive-positive type, in particular, as a light-sensitive copyingcomposition for a printing original or as a photoresist composition forphotoetching, for example, as disclosed in U.S. Pat. No. 3,181,461.These compositions comprise generally not only an O-quinone diazidecompound but also an alkali-soluble resin such as a phenol-formaldehyderesin and a styrene-maleic anhydride copolymer to reinforce the imagestrength and to increase the film-forming properties, and can preferablybe used in the form of a uniform composition, in addition, withadditives such as dyes and plasticizers.

However, the O-quinone diazide-containing light-sensitive material ofthe prior art has the disadvantage that a considerable thickness, forexample, 0.5 to 10 microns is necessary in order to obtain a sufficientimage strength and thus a large amount of 0-quinone diazide compoundmust be used. As a result the light sensitivity is low as a copyinglayer. Furthermore, the resin for increasing the image strength shouldbe miscible with O-quinone diazide compounds and only a narrow selectionof materials is suitable. Therefore, the reinforcing of an image can notbe advantageously carried out.

SUMMARY OF THE INVENTION

Efforts to overcome these disadvantages have been made and,consequently, it has been found that the above described problems can besolved by laminating a support member with a plurality of organiccoating layers, at least one layer of which comprises an O-quinonediazide compound.

That is to say, the present invention provides a light-sensitive copyingmaterial comprising at least two organic coating layers on a support, atleast one of the coating layers being a light-sensitive layer whichcomprises an O-quinone diazide and whose solubility in an alkalinesolution is increased upon irradiation of active rays.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

FIGS. 1a, 1b, and 1c are a cross sectional view of one embodiment of thelight-sensitive copying material of the invention.

FIGS. 2a, 2b, and 2c are a cross sectional view of a copying material inthe main steps of forming an image.

FIG. 3 is a cross sectional view of another embodiment of thelight-sensitive copying material of the invention.

DETAILED DESCRIPTION OF THE INVENTION

The layer structure of the light-sensitive copying material according tothe invention can be roughly classified into two types. Each of thelayer structures and a method of forming an image using thelight-sensitive copying material will now be illustrated with referenceto the accompanying drawings.

FIG. 1 (a) is a cross sectional view of a first layer structure of thelight-sensitive copying material according to the invention, in which alight-sensitive organic coating layer 2 of an O-quinone diazide compoundand an organic coating layer 3 different from layer 2 are provided inorder on a support member 1. The above described organic coating layerhas the property that it is barely soluble in the developer used afterexposure and permeable to the developer employed. In FIG. 1 (b), thelight-sensitive copying material of FIG. 1 (a) is exposed to active raysthrough an original and thus the exposed area 2a of the organic coatinglayer 2 is rendered alkali-soluble. When this exposed light-sensitivecopying material is treated with an alkaline solution, the alkalinesolution permeates the organic coating layer 3 and dissolves the organiccoating layer 2a and is completely removed with the organic coatinglayer 3a. Then, the support 1 is exposed and an image is formed as shownin FIG. 1 (c).

FIG. 2 (a) is a cross sectional view of a second layer structure of thelight-sensitive copying material according to the invention, in which anorganic coating layer 4 and a light-sensitive organic coating layer 5 ofan O-quinone diazide compound are provided in order on a supportmember 1. In this case, the organic coating layer 4 is dissolved in orswelled by the developer applied after exposure and readily stripped. InFIG. 2 (b), the light-sensitive copying material of FIG. 2 (a) isexposed to active rays through an original and thus the exposed area 5aof organic coating layer 5 is rendered alkali-soluble. When this exposedlight-sensitive copying material is treated with an alkaline developer,the organic coating layer 5a is dissolved and removed and then the lowerorganic coating layer 4a is also removed, with support 1 thus beingexposed. On the other hand, the non-exposed area 5b is not removed by analkaline developer, and the lower organic coating layer 4b is protectedfrom the developer and remains as it is, thus forming an image as shownin FIG. 2 (c).

FIG. 3 shows a cross sectional view of another layer structure of thelight-sensitive copying material according to the invention, in which alight-sensitive organic coating layer 6 of an O-quinone diazidecompound, an organic coating layer 7 and a light-sensitive organiccoating layer 8 of an O-quinone diazide compound are in order providedon a support 1. In this layer structure, the organic coating layer 7 ispermeable to an alkaline developer or is dissolved in or swelled by analkaline developer.

Suitable supports of the invention which can be used are metal sheetssuch as aluminum or aluminum alloy sheets, zinc sheets and coppersheets, nitrocellulose films, cellulose diacetate films, cellulosetriacetate films, cellulose butyrate films, cellulose acetate butyratefilms, polyethylene terephthalate films, polystyrene films,polycarbonate films, polyethylene films, polypropylene films, papers,polyethylene- or polystyrene-laminated papers and glass sheets. Wherethe light-sensitive copying material of the invention is used as alight-sensitive lithographic printing plate, in particular, the surfaceof a support should be hydrophilic. In this case, an aluminum sheet ismost preferably used as the support, which is preferably surface treatedby sand blasting, with a phosphate or potassium fluozirconate or byanodic oxidation. Furthermore, an aluminum sheet subjected to atreatment with an aqueous solution of sodium silicate after sandblasting as described in U.S. Pat. No. 2,714,066 and an aluminum sheetsubjected to an anodic oxidation treatment and then to a treatment withan aqueous solution of an alkali metal silicate as described in U.S.Pat. No. 3,181,461 are preferably used. The above described anodicoxidation treatment is, for example, carried out by passing an electriccurrent through an aluminum sheet as anode in an electrolyte of one ormore of aqueous or non-aqueous solutions of inorganic acids such asphosphoric acid, chromic acid, sulfuric acid and boric acid and organicacids such as oxalic acid and sulfamic acid.

On the other hand, the O-quinone diazide compound of the invention canbe selected from a great number of compounds of various structureshaving at least one O-quinone diazide group, in which thealkali-solubility is increased upon irradiation with active rays. SuchO-quinone diazide compounds are described in detail in J. Kosar,Light-Sensitive Systems, p. 339-352, John Wiley & Sons, Inc., which canbe used in the present invention. In particular, various aromaticpolyhydroxy compounds and O-quinone diazide sulfonic acid esters arepreferred. Illustrative of the aromatic polyhydroxy compounds arehydroquinone, catechol, 2,2'-dihydroxybiphenyl, 4,4'-dihydroxybiphenyl,4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxydiphenyl sulfide,4,4'-dihydroxydiphenyl sulfone, 4,4'-dihydroxydiphenylmethane, bisphenolA, 1,8-dihydroxynaphthalene, 2,7-dihydroxynaphthalene,1,4-dihydroxynaphthalene, 2,3-dihydroxynaphthalene,2,2'-dihydroxy-1,1'-dinaphthylmethane, 4,4'-dihydroxybenzophenone,α,β-bis-(4-hydroxyphenyl)ethane, 1,4-dihydroxyanthraquinone,2,7-dihydroxyfluorene, pyrogallol, methyl gallate,2,2',4,4'-tetrahydroxybiphenyl and tetrahydroxybenzoquinone.

Typical examples of aromatic polyhydroxy compounds and O-quinone diazidesulfonic acid esters are2,2'-dihydroxy-diphenyl-bis-(naphthoquinone-1,2-diazide-5-sulfonic acidester), 2,3,4-trioxybenzophenone-bis-(naphthoquinone-1,2-diazide-5-sulfonic acid ester),2,7-dihydroxynaphthalene-bis-(naphthoquinone-1,2-diazide-5-sulfonic acidester) and the ester of a phenol-formaldehyde resin andnaphthoquinone-1,2-diazide-5-sulfonic acid. Above all,napthoquinone-1,2-diazide-5-sulfonic acid ester of thepolyhydroxy-phenyl obtained by the polycondensation of acetone andpyrogallol described in U.S. Pat. No. 3,635,709 can be advantageouslyused.

The O-quinone diazide compound of the invention alone or in admixturewith a resin is coated as a layer on a desired position onto a supportto provide a light-sensitive organic coating layer. As the resin to bemixed with the O-quinone diazide compound, alkali-soluble resins, forexample, phenol resins, cresol resins, styrene/maleic anhydridecopolymers and shellac are suitable. Since a thinner light-sensitiveorganic coating layer in the light-sensitive copying material of theinvention can be employed than the light-sensitive layer of single layerof the prior art, resins barely soluble in alkali solutions, which havehitherto not been mixed, for example, p-phenylphenol-formaldehyderesins, p-t-butylphenol-formaldehyde resins and polyvinyl butyral, canbe used for the purpose of increasing the strength of an image area.

When the O-quinone diazide compound is used in admixture with one ormore of these resins, it is desirable that the O-quinone diazidecompound be present in an amount of at least about 20% by weight. If thecontent of O-quinone diazide is less than 20% by weight, a sufficientsensitivity and sharp image cannot be obtained.

A composition comprising an O-quinone diazide compound, which comprisesthe light-sensitive organic coating layer, is dissolved in a suitablesolvent and coated. Examples of suitable solvents are ethylene glycolmonoalkyl ethers such as ethylene glycol monomethyl ether and ethyleneglycol monoethyl ether, their acetic acid esters such as ethylene glycolmonomethyl ether acetate and ethylene glycol monoethyl ether acetate,ketones such as methyl ethyl ketone, methyl isobutyl ketone andcyclohexanone, butyl acetate, dioxane, pyridine and dimethylformamide.

The organic coating layer other than the light-sensitive organic coatinglayer used in the invention comprises a water-insoluble but organicsolvent-soluble high molecular weight compound having film formingproperties. In the layer structure of the first type as described above,furthermore, the second layer, the light-non-sensitive layer is notdissolved in a developer more readily than the light-sensitive part ofthe first layer and should be permeable to the developer. For example,the light-non-sensitive layer can comprise a styrene/maleic anhydridecopolymer, a styrene/acrylic acid copolymer, polyvinyl butyral, shellacor a soluble polyamide resin.

In the layer structure of the second type, the lower layer that isreadily removed by a developer is protected by the upper non-exposedlayer to provide an image. Thus, it is necessary that the lower layer bereadily dissolved in a developer or swelled and stripped. For example,phenol-formaldehyde resins, cresol-formaldehyde resins, polyvinylhydrogen phthalate and methacrylic acid/methyl methacrylate copolymersare suitable for this purpose. On the other hand, in the case of thethird type as shown in FIG. 3, the stability of the image is better indevelopment than in the first and second types and any resins suitablefor the first type or for the second type can be used.

In any of the first, second and third types, each layer can be of notonly one resin but also a mixture of various resins to control thedissolving or swelling properties in developers and the coatingproperties. Moreover, an O-quinone diazide compound can be added tothese resins within a range which does not render them light-sensitive.

If desired, various organic or inorganic additives can be incorporatedin a suitable amount in the organic coating. For example, dyes (such asCrystal Violet and Oil blue) in an amount of about 0.5 to 5% by weight,or pigments (such as Phthalocyanine Blue) in an amount of about 5 to 40%by weight can be added to color the coating, and fillers or plasticizers(such as titanium dioxide and clays) each in an amount of about 5 to30%, can be added to increase the mechanical strength of the coating.

The dissolving, swelling and stripping properties of thelight-insensitive layers of the first and second types depend upon thestrength of the developer suitable for the light-sensitive layer used.As is well known in the art, the strength of a developer differsdepending on the composition of the O-quinone diazide light-sensitivelayer and, in general, a suitable range of developer strength which canbe used broadens with the increase in the content of the O-quinonediazide light-sensitive layer. The strength of a developer can suitablybe selected within this range. Therefore, the selection of a resin ofthe first type or second type need not be based on the degree ofordinary dissolving or swelling only and, on the other hand,styrene/maleic anhydride copolymers or styrene/acrylic acid copolymerscan be used for any type by the selection of a light-sensitivecomposition.

The method of laminating the organic coatings according to the inventionis ordinarily carried out by repeated coating of the layer componentsfollowed by drying, but, of course, various coating methods such ascasting, transferring and simultaneous multi-layer coating can be used.

The thickness of each layer in the light-sensitive copying materialaccording to the invention ranges, irrespective of the layer structure,from about 0.01 g/m² to 7.0 g/m², preferably from 0.02 g/m² to 5.0 g/m²on a dry basis, and the thickness of a light-sensitive organic coatinglayer comprising an O-quinone diazide compound is preferably 3.0 g/m² orless. Moreover, the sum of organic coating layers provided on a supportis preferably 7.0 g/m² or less.

The light-sensitive copying material of the present invention isimagewise exposed to active rays such as radiation from a mercury lamp,xenon lamp or carbon arc lamp and then developed. While the exposuretime and the amount of exposure can vary, a suitable exposure time canrange from about 5 seconds to 5 minutes, preferably about 5 seconds to 1minute. Suitable developers which can be used are alkali solutions,which have hitherto been known as developers for a light-sensitive layerof an O-quinone diazide compound, for example, aqueous solutions ofinorganic alkalis such as sodium hydroxide, potassium hydroxide, sodiumsilicate, potassium silicate, sodium triphosphate, potassiumtriphosphate, sodium carbonate and potassium carbonate and basicsolvents such as monoethanolamine, diethanolamine, propanolamine andmorpholine. A suitable developer solution concentration can range fromabout 1 to 20% by weight, preferably 3 to 15% by weight. If desired,organic solvents and surface active agents can be added to these aqueoussolutions. Where the wetting and permeation of the developer is reducedby the use of laminated organic coatings than the wetting and permeationof an O-quinone diazide light-sensitive layer alone, it is desirable toadd a suitable amount of an organic solvent such as n-propyl alcohol ora surfactant such as sodium lauryl sulfate.

The light-sensitive copying material of the invention has an advantagethat the strength of the image can be improved without increasing thethickness of the light-sensitive layer and, consequently, the amount ofthe O-quinone diazide can be reduced, resulting in obtaining a highsensitivity. Moreover, since an organic coating layer is provided inaddition to a light-sensitive layer, the range of resins which can beselected for strengthening the image is broadened and a resin having adesirable properties can be selected depending on the end-use objects.

The light sensitive copying material of the invention is applicable tovarious uses such as production of originals for overhead projectors andname plates in addition to the production of printing plates.

The following examples are given in order to illustrate the invention ingreater detail without limiting the same. Unless otherwise, all parts,percents, ratios and the like are by weight.

EXAMPLE 1

1 part by weight of an ester of naphthoquinone-1,2-diazide-5-sulfonicacid and the polyhydroxy-phenyl obtained by the polycondensation ofacetone and pyrogallol as described in Example 1 of U.S. Pat. No.3,635,709 was dissolved in 100 parts by weight of ethylene glycolmonomethyl ether and coated onto a grained aluminum sheet of a thicknessof 0.3 mm in an amount of 25 ml per 1 m². After drying, thelight-sensitive layer of O-quinone diazide compound had a thickness ofabout 0.25 g/m². The above described light-sensitive layer was confirmedto be barely soluble in a mixed solution of n-propyl alcohol and methylalcohol (1:1 by volume). 8 parts by weight of a styrene-maleic acidanhydride copolymer (molar ratio 7:3; ethyl ester; approximate molecularweight: 100,000) and 0.05 part by weight of a dye (Oil Blue,manufactured by Orient Kagaku Co., Ltd.) were dissolved in 100 parts byweight of the mixed alcohol solution and coated onto the resultingO-quinone diazide light-sensitive layer so as to give a thickness of 2.0g/m² on a dry basis.

The so laminated light-sensitive plate was contacted tightly with atransparent positive image, exposed for 20 seconds to radiation from acarbon arc lamp light source (45 amp, 3 phase) at a distance of 70 cmand developed with a 3% by weight aqueous solution of sodium silicate.The exposed area was removed and a positive image corresponding to theoriginal was obtained. It was found, from the condition of the imagearea colored with the dye, that the laminated first layer and secondlayer gave an image in combination. This plate was used as an offsetprinting plate in a conventional manner to thus obtain a very goodprint.

This good result was obtained with an exposure quantity of about half orless of that necessary for many commercially available light-sensitiveprinting plates using O-quinone diazide compounds.

EXAMPLE 2

The procedures of Example 1 were repeated except a shellac resin(manufactured by Nippon Shellac Kogyo Co., Ltd.) was used in place ofthe styrene-maleic acid copolymer, thus obtaining a light-sensitiveplate. This plate was developed with 1% by weight aqueous solution ofsodium silicate, gave a high sensitivity similar to Example 1 and had asufficient properties that it could be used as an offset printing plate.

EXAMPLE 3

The procedures of Example 1 were repeated except a transparentpolyethylene terephthalate film of a thickness of 0.1 mm was used inplace of the grained aluminum sheet, thus obtaining a laminatedlight-sensitive plate. After developing, a transparent sheet having ablue image was obtained, which was suitable for use as an original forprojection.

EXAMPLE 4

On the grained aluminum sheet similar to that of Example 1 was formed afirst light-sensitive layer of an ester ofnaphthoquinone-1,2-diazide-5-sulfonic acid with polyhydroxyphenyl thatis the condensation product of acetone and pyrogallol. 4 parts by weightof an alcohol-soluble nylon (Toray Amilan 4000 CM) was dissolved in 100parts by weight of a mixed solution of n-propyl alcohol and methylalcohol (1:1 by volume) and coated onto the above described O-quinonediazide light-sensitive layer to give a thickness of about 1.0 g/m² ondry basis, followed by drying. The so obtained light-sensitive plate wascontacted tightly with a positive image, exposed imagewise for only 20seconds to radiation from a carbon arc lamp light source (45 amp, 3phase) through a distance of 70 cm and then developed with an aqueoussolution containing 3% by weight of sodium silicate and 0.8% by weightof sodium lauryl sulfate. The resulting image was excellent in wearresistance as well as in resistance to scratching. When this plate wasused as an offset printing plate, 50,000 or more good prints wereobtained.

An attempt to mix the above described O-quinone diazide compound andnylon to form a single light-sensitive layer was not satisfactory,because they were not miscible and turbidity resulted.

EXAMPLE 5

In a manner similar to Example 4, on a grained aluminum sheet wereformed a first light-sensitive layer of the O-quinone diazide compoundin a thickness of about 0.25 g/m² and a second alcohol-soluble nylonlayer in a thickness of about 1.0 g/m², thus obtaining a laminatedlight-sensitive plate. It was found that this light-sensitive plate wasnot dissolved by ethylene glycol monomethyl ether. Then 0.5 part byweight of the O-quinone diazide compound used in Example 1, 1.5 parts byweight of phenolformaldehyde novolak resin and 0.02 part by weight of adye (Oil Blue, manufactured by Orient Kagaku Co., Ltd.) were dissolvedin 100 parts by weight of ethylene glycol monomethyl ether to prepare athird coating solution and coating onto the above describedlight-sensitive plate in a thickness of 0.5 g/m² on a dry basis followedby drying. The resulting light-sensitive plate of a three layerstructure was used as a printing plate in a manner similar to Example 4.This printing plate had a tenacious image as well as a high printingresistance and the oil-sensitivity of the image was more improved thanin the case of Example 4. A number of prints having a sufficient inkdensity were obtained except for the production several bad qualityprints at the start of printing.

EXAMPLE 6

10 parts by weight of a methacrylic acid/methyl methacrylate copolymer(copolymerization molar ratio, 2/8; average molecular weight, about70,000) and 0.1 part by weight of a dye (Oil Pink, manufactured byOrient Kagaku Co., Ltd.) were dissolved in 100 parts of ethylene glycolmonomethyl ether and coated onto a grained aluminum sheet of 0.3 mm in athickness in a proportion of 2.0 g/m² on a dry basis followed by drying.Then 2 parts by weight of an ester of a cresol-formaldehyde novolak typeresin and naphthoquinone-1,2-diazide-5-sulfonic acid were dissolved in100 parts by weight of methylene dichloride and coated onto the abovedescribed layer of the methacrylic acid/methyl methacrylate copolymerand dye in a thickness of 0.5 g/m² on a dry basis, followed by drying.The so laminated light-sensitive plate was so sensitive that adifference in solubility on the upper layer of the light-sensitive plateby contacting tightly with a positive image and exposing imagewise foronly 15 seconds to radiation from a carbon arc lamp light source (45amp, 3 phase) at a distance of 70 cm occurred, and the exposed area wasreadily removed with an aqueous solution containing 3% by weight ofsodium silicate. Since the methacrylic acid/methyl methacrylatecopolymer of the first layer was an alkali-soluble polymer, moreover,the development was rapidly effected and an offset printing plateexcellent in tone reproduction was obtained.

EXAMPLE 7

10 parts by weight of a phenol-formaldehyde novolak resin and 0.5 partby weight of an ester of naphthoquinone-1,2-diazide-5-sulfonic acid withpolyhydroxy-phenyl that is the condensation product of acetone andpyrogallol, as used in Example 1, were dissolved in 100 parts by weightof ethylene glycol monomethyl ether acetate. The resulting solution wascoated onto an aluminum plate of a thickness of 0.3 mm, subjected to agraining and an anodic oxidation treatment (15% by weight sulfuric acid;current density, 1.6 amp/dm² ; time, 2 minutes) to give a thickness of2.1 g/m² on a dry basis, thus forming a first layer. Then 2 parts byweight of the phenol-formaldehyde resin used in the first layer and 5parts by weight of2,2'-dihydroxy-diphenyl-bis-(naphthoquinone-1,2-diazide-5-sulfonic acidester) were dissolved in 150 parts of methylene dichloride and coatedonto the above described first layer to give a coating quantity of 0.5g/m² on a dry basis. Thereafter, treatment similar to that in Example 6was carried out to form an image. The thus laminated light-sensitiveplate had a high sensitivity as well as a good tone reproduction and wasimproved in development stability to a greater extent. Moreover, thesensitive plate had sufficient properties as an offset printing plate.

While the invention has been described in detail and with reference tospecific embodiments thereof, it will be apparent to one skilled in theart that various changes and modifications can be made therein withoutdeparting from the spirit and scope thereof.

What is claimed is:
 1. A light-sensitive material consisting essentiallyof (1) a support having a hydrophilic surface, and (2) in order on saidsurface a first light-sensitive layer adjacent said support containingan O-quinone diazide compound alone or in admixture with resin, saidfirst light-sensitive layer containing 20 to 100% by weight of theortho-quinone diazide compound, the alkali solubility of said compoundbeing increased upon irradiation with active rays, a non-light sensitiveorganic coating layer over said first light-sensitive layer, and asecond light-sensitive layer containing an O-quinone diazide compoundalone or in admixture with resin, said second light-sensitive layercontaining 20 to 100% by weight of the orthoquinone diazide compound,the alkali solubility of said compound being increased upon irradiationwith active rays, over said organic coating layer, said organic coatinglayer comprising a water-insoluble but organic solvent-soluble highmolecular weight compound having film forming properties and furtherhaving the property that it is either permeable to an alkaline developeror is dissolved in or swelled by an alkaline developer, the thickness ofeach of said layers on said support ranging from about 0.1 g/m.sup. 2 to7.0 g/m².
 2. The light sensitive material of claim 1, wherein saidsupport is a metal sheet, a resin film, a paper, a resin film-paperlaminate, or a glass sheet.
 3. The light-sensitive material of claim 1,wherein said support is an aluminum sheet.
 4. The light-sensitivematerial of claim 1, wherein said O-quinone diazide compound is an esterof an aromatic polyhydroxy compound and an O-quinone diazide sulfonicacid.
 5. The light-sensitive material of claim 4, wherein said O-quinonediazide compound is2,2'-dihydroxy-diphenyl-bis-(naphthoquinone-1,2-diaxide-5-sulfonic acidester),2,3,4-trioxybenzophenone-bis-(naphthoquinone-1,2-diazide-5-sulfonic acidester), 2,7-dihydroxynaphthalene-bis-(naphthoquinone-1,2-diazide-5-sulfonic acid ester), the ester of a phenolformaldehyde resin andnaphthoquinone-1,2-diazide-5-sulfonic acid, or the naphthoquinone-1,2-diazide-5-sulfonic acid ester of the polyhydroxyphenyl obtained bythe condensation of acetone and pyrogallol.
 6. The light sensitivematerial of claim 1, wherein said first and second light-sensitive layercomprises said O-quinone diazide compound and an organic resin.
 7. Thelight-sensitive material of claim 6 wherein said organic resin is aphenol resin, a cresol resin, a styrene/mallic anhydride copolymer orshellac.
 8. The light sensitive material of claim 1, wherein thecombined thickness of said coating layers is 7.0 g/m² or less.
 9. Amethod of forming an image comprising image-wise exposing thelight-sensitive material of claim 1 and developing the exposedlight-sensitive material.